Gut microbiome analysis as a tool towards targeted non-invasive biomarkers for early hepatocellular carcinoma

The mechanism of dysbiosis in alcoholic liver disease leading to liver cancer

Currently, alcoholic liver disease (ALD) is one of the most prevalent chronic liver diseases worldwide, representing one of the main etiologies of cirrhosis and hepatocellular carcinoma (HCC). Although we do not know the exact mechanisms by which only a selected group of patients with ALD progress to the final stage of HCC, the role of the gut microbiota within the progression to HCC has been intensively studied in recent years. To date, we know that alcohol-induced gut dysbiosis is an important feature of ALD with important repercussions on the severity of this disease. In essence, an increased metabolism of ethanol in the gut induced by an excessive alcohol consumption promotes gut dysfunction and bacterial overgrowth, setting a leaky gut. This causes the translocation of bacteria, endotoxins, and ethanol metabolites across the enterohepatic circulation reaching the liver, where the recognition of the pathogen-associated molecular patterns via specific Toll-like receptors of liver cells will induce the activation of the nuclear factor kappa-B pathway, which releases pro-inflammatory cytokines and chemokines. In addition, the mitogenic activity of hepatocytes will be promoted and cellular apoptosis will be inhibited, resulting in the development of HCC. In this context, it is not surprising that microbiota-regulating drugs have proven effectiveness in prolonging the overall survival of patients with HCC, making attractive the implementation of these drugs as co-adjuvant for HCC treatment.

Identification of Multigene Biomarker for Shrimp White Feces Syndrome by Full-Length Transcriptome Sequencing

The pacific white shrimp, Litopenaeus vannamei, with the largest shrimp industry production in the world, is currently threatened by a severe disease, white feces syndrome (WFS), which cause devastating losses globally, while its causal agents remain largely unknown. Herein, compared to the Control shrimp by metagenomic analysis, we firstly investigated that the altered functions of intestinal microbial community in WFS shrimp were the enrichment of bacterial chemotaxis and flagellar assembly pathways, hinting at a potential role of pathogenic bacteria for growth and development, which might be related to WFS occurrence. Single-molecule real-time (SMRT) sequencing was to further identify the gene structure and gene regulation for more clues in WFS aetiology. Totally 50,049 high quality transcripts were obtained, capturing 39,995 previously mapped and 10,054 newly detected transcripts, which were annotated to 30,554 genes. A total of 158 differentially expressed genes (DEGs) were characterized in WFS shrimp. These DEGs were strongly associated with various immune related genes that regulated the expression of multiple antimicrobial peptides (e.g., antilipopolysaccharide factors, penaeidins, and crustin), which were further experimentally validated using quantitative PCR on transcript level. Collectively, multigene biomarkers were identified to be closely associated with WFS, especially those functional alterations in microbial community and the upregulated immune related gene with antibacterial activities. Our finding not only inspired our cogitation on WFS aetiology from both microbial and host immune response perspectives with combined metagenomic and full-length transcriptome sequencing, but also provided valuable information for enhancing shrimp aquaculture.

Screening and verification of microRNA promoter methylation sites in hepatocellular carcinoma

The promoter methylation mode of microribonucleic acid (miRNA) plays a crucial role in the process of hepatocellular carcinoma (HCC). Therefore, the primary purpose of this study was to screen and verify the miRNA methylation sites associated with the overall survival (OS) and clinical characteristics of HCC patients. Methylation-related data were from the Cancer Genome Atlas (TCGA). R software was utilized to screen the methylation sites. The least absolute shrinkage and selection operator algorithm was utilized to develop the miRNA promoter methylation models. Then, methylation-specific polymerase chain reaction was performed with 146 HCC tissues to verify the accuracy of the vascular infiltration-related model. Additionally, we verified the functions of vascular infiltration-related miRNA by utilizing cells transfected with miR-199a-3p mimic. The model for predicting OS of HCC patients contained eight methylation sites. The Kaplan-Meier analysis suggested that the model could divide HCC patients into high- and low-risk groups (P < .0001). COX regression analysis suggested that the model (P < .001; 95% CI, 1.264-2.709) and T category (P < .001; 95% CI, 1.472-3.119) were independent risk factors for affecting OS of HCC patients. The model for predicting vascular infiltration, pathological grade, and clinical stage contained 7, 10, and 9 methylation sites respectively, with their area under the receiver operating characteristic curve (AUC) values 0.667, 0.745, and 0.725, respectively. The functional analysis suggested that miRNA methylation is involved in various biological processes such as WNT, MAPK, and mTOR signaling pathways. The accuracy of the vascular infiltration-related model was consistent with our previous bioinformatics assay. And upregulation of miR-199a-3p decreased migration and invasion abilities. The screened miRNA promoter methylation sites can be served as biomarkers for judging OS, vascular infiltration, pathology grade, and clinical stage. It can also provide new targets for improving the treatment and prognosis of HCC patients.

Gut microbiome in HCC - Mechanisms, diagnosis and therapy

The microbiome exerts essential functions in health and disease, modulating key processes in metabolism, inflammation and immunity. Recent evidence has revealed a key role of the microbiome in carcinogenesis as well as anti-cancer immune responses in mouse models and patients. Herein, we will review functions of the gut microbiome in hepatocellular carcinoma (HCC), the third leading cause of worldwide cancer mortality. The majority of HCC develops in patients with chronic liver disease, caused by viral hepatitis, non-alcoholic fatty liver disease (NAFLD) and alcohol-related fatty liver disease. In this review, we will discuss mechanisms by which the gut-liver axis promotes the development of HCC in mouse models and patients, including dysbiosis, the leaky gut and bacterial metabolites, with a particular focus on NAFLD as the fastest growing cause of HCC development. Moreover, we will review recent progress in harnessing the gut microbiome as a potential diagnostic tool and novel therapeutic target in patients with HCC, in particular in the setting of immunotherapy.

Development and validation of a simple risk model to predict major cancers for patients with nonalcoholic fatty liver disease

OBJECTIVE

To recognize risk factors and build up and validate a simple risk model predicting 8-year cancer events after nonalcoholic fatty liver disease (NAFLD).

METHODS

This was a retrospective cohort study. Patients with NAFLD (n = 5561) were randomly divided into groups: training (n = 1254), test (n = 627), evaluation (n = 627), and validation (n = 3053). Risk factors were recognized by statistical method named as a Cox model with Markov chain Monte Carlo (MCMC) simulation. This prediction score was established based on the training group and was further validated based on the testing and evaluation group from January 1, 2007 to December 31, 2009 and another 3053 independent cases from January 1, 2010 to February 13, 2014.

RESULTS

The main outcomes were NAFLD-related cancer events, including those of the liver, breast, esophagus, stomach, pancreas, prostate and colon, within 8 years after hospitalization for NAFLD diagnosis. Seven risk factors (age (every 5 years),LDL, smoking, BMI, diabetes, OSAS, and aspartate aminotransferase (every 5 units)) were identified as independent indicators of cancer events. This risk model contained a predictive range of 0.4%-37.7%, 0.3%-39.6%, and 0.4%-39.3% in the training, test, evaluation group, respectively, with a range 0.4%-30.4% for validation groups. In the training group, 12.6%, 76.9%, and 10.5% of patients, which corresponded to the low -, moderate -, and high-risk groups, had probabilities of, <0.01, <0.1, and 0.23 for 8-year events.

CONCLUSIONS

Seven risk factors were recognized and a simple risk model were developed and validated to predict the risk of cancer events after NAFLD based on 8 years. This simple risk score system may recognize high-risk patients and reduce cancer incidence.

Gut microbiota dysbiosis in patients with hepatitis B virus-induced chronic liver disease covering chronic hepatitis, liver cirrhosis and hepatocellular carcinoma

The information regarding the effect of hepatitis B virus (HBV) infection on gut microbiota and the relationship between gut microbiota dysbiosis and hepatitis B virus-induced chronic liver disease (HBVCLD) is limited. In this study, we aimed at characterizing the gut microbiota composition in the three different stages of hepatitis B virus-induced chronic liver disease patients and healthy individuals. Faecal samples and clinical data were collected from HBVCLD patients and healthy individuals. The 16S rDNA gene amplification products were sequenced. Bioinformatic analysis including alpha diversity and PICRUSt was performed. A total of 19 phyla, 43 classes, 72 orders, 126 families and 225 genera were detected. The beta-diversity showed a separate clustering of healthy controls and HBVCLD patients covering chronic hepatitis (CHB), liver cirrhosis (LC) and hepatocellular carcinoma (HCC); and gut microbiota of healthy controls was more consistent, whereas those of CHB, LC and HCC varied substantially. The abundance of Firmicutes was lower, and Bacteroidetes was higher in patients with CHB, LC and HCC than in healthy controls. Predicted metagenomics of microbial communities showed an increase in glycan biosynthesis and metabolism-related genes and lipid metabolism-related genes in HBVCLD than in healthy individuals. Our study suggested that HBVCLD is associated with gut dysbiosis, with characteristics including, a gain in potential bacteria and a loss in potential beneficial bacteria or genes. Further study of CHB, LC and HCC based on microbiota may provide a novel insight into the pathogenesis of HBVCLD as well as a novel treatment strategy.

Advances in the early diagnosis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers globally. In contrast to the declining death rates observed for all other common cancers such as breast, lung, and prostate cancers, the death rates for HCC continue to increase by ~2–3% per year because HCC is frequently diagnosed late and there is no curative therapy for an advanced HCC. The early diagnosis of HCC is truly a big challenge. Over the past years, the early diagnosis of HCC has relied on surveillance with ultrasonography (US) and serological assessments of alpha-fetoprotein (AFP). However, the specificity and sensitivity of US/AFP is not satisfactory enough to detect early onset HCC. Recent technological advancements offer hope for early HCC diagnosis. Herein, we review the progress made in HCC diagnostics, with a focus on emerging imaging techniques and biomarkers for early disease diagnosis.

Gut microbiota: A new piece in understanding hepatocarcinogenesis

The gut microbiota forms a symbiotic relationship with the host and benefits the body in many critical aspects of life. However, immune system defects, alterations in the gut microbiota and environmental changes can destroy this symbiotic relationship and may lead to diseases, including cancer. Due to the anatomic and functional connection of the gut and liver, increasing studies show the important role of the gut microbiota in the carcinogenesis of hepatocellular carcinoma (HCC). In this manuscript, we review the available evidence and analyze some potential mechanisms of the gut microbiota, including bacterial dysbiosis, lipopolysaccharide (LPS), and genotoxins, in the progression and promotion of HCC. Furthermore, we discuss the possible therapeutic applications of probiotics, chemotherapy modulation, immunotherapy, targeted drugs and fecal microbiota transplantation (FMT) in targeting the gut microbiota.

Fecal microbiota as a noninvasive biomarker to predict the tissue iron accumulation in intestine epithelial cells and liver

Iron is an essential trace mineral required for growth, metabolism, and immune response. Dysregulation of iron homeostasis is linked with the development and progression of various diseases. Iron accumulation is associated with inflammatory diseases and cancer, while iron deficiency leads to the growth retardation. Several studies have suggested that iron imbalance results in alteration of gut microbiota, leading to the disruption of microbial diversity, the increase of pathogen abundance, and the induction of intestinal inflammation. However, in screening studies done in the past decades, the association between the iron availability and gut microbiota has not been systemically explored. Furthermore, a noninvasive and convenient approach to determine the iron levels in tissues is lacking. In the present study, a murine model for iron dysregulation was established. 16S rRNA amplicon sequencing and bioinformatic algorithms were used to identify the key taxa. Using the key taxa identified and machine learning models, we established an easily accessible prediction model, which could accurately distinguish between iron-deprived or iron-fortified condition. This prediction model could precisely predict the iron level of the intestinal epithelial cells and the liver and could be used for early diagnosis of iron dysbiosis-related diseases, in a noninvasive manner, in the future.

Gut Microbiota and Liver Injury (II): Chronic Liver Injury

Chronic liver injury mainly comprises viral hepatitis, fatty liver disease, autoimmune hepatitis, cirrhosis and liver cancer. It is well established that gut microbiota serves as the key upstream modulator for chronic liver injury progression. Indeed, the term "gut-liver axis" was mostly applied for chronic liver injury. In the current chapter, we will summarize the relationship between gut microbiota and chronic liver injury, including the interaction between them based on latest clinic and basic research.

Nanoparticle Conjugation of Ginsenoside Rg3 Inhibits Hepatocellular Carcinoma Development and Metastasis

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. The prognosis of HCC remains very poor; thus, an effective treatment remains urgent. Herein, a type of nanomedicine is developed by conjugating Fe@Fe3 O4 nanoparticles with ginsenoside Rg3 (NpRg3), which achieves an excellent coupling effect. In the dimethylnitrosamine-induced HCC model, NpRg3 application significantly prolongs the survival of HCC mice. Further research indicates that NpRg3 application significantly inhibits HCC development and eliminates HCC metastasis to the lung. Notably, NpRg3 application delays HCC-induced ileocecal morphology and gut microbial alterations more than 12 weeks during HCC progression. NpRg3 administration elevates the abundance of Bacteroidetes and Verrucomicrobia, but decreases Firmicutes. Twenty-nine predicted microbial gene functions are enriched, while seven gene functions are reduced after NpRg3 administration. Moreover, the metabolomics profile presents a significant progression during HCC development, but NpRg3 administration corrects tumor-dominant metabolomics. NpRg3 administration decreases 3-indolepropionic acid and urea, but elevates free fatty acids. Importantly, NpRg3 application remodels the unbalanced correlation networks between gut microbiota and metabolism during HCC therapy. In conclusion, nanoparticle conjugation of ginsenoside Rg3 inhibits HCC development and metastasis via the remodeling of unbalanced gut microbiota and metabolism in vivo, providing an antitumor therapy strategy.

Association of suboptimal health status with intestinal microbiota in Chinese youths

Suboptimal health status (SHS), a physical state between health and disease, is a subclinical and reversible stage of chronic disease. Previous studies have shown alterations in the intestinal microbiota in patients with some chronic diseases. This study aimed to investigate the association between SHS and intestinal microbiota in a case-control study with 50 SHS individuals and 50 matched healthy controls. Intestinal microbiota was analysed by MiSeq 250PE. Alpha diversity of intestinal microbiota in SHS individuals was higher compared with that of healthy controls (Simpson index, W = 2238, P = .048). Beta diversity was different between SHS and healthy controls (P = .018). At the phylum level, the relative abundance of Verrucomicrobia was higher in the SHS group than that in the controls (W = 2201, P = .049). Compared with that of the control group, nine genera were significantly higher and five genera were lower in abundance in the SHS group (all P < .05). The intestinal microbiota, analysed by a random forest model, was able to distinguish individuals with SHS from the controls, with an area under the curve of 0.79 (95% confidence interval: 0.77-0.81). We demonstrated that the alteration of intestinal microbiota occurs with SHS, an early stage of disease, which might shed light on the importance of intestinal microbiota in the primary prevention of noncommunicable chronic diseases.

Our Microbiome: On the Challenges, Promises, and Hype

The microbiome field is increasingly raising interest among scientists, clinicians, biopharmaceutical entities, and the general public. Technological advances from the past two decades have enabled the rapid expansion of our ability to characterize the human microbiome in depth, highlighting its previously underappreciated role in contributing to multifactorial diseases including those with unknown etiology. Consequently, there is growing evidence that the microbiome could be utilized in medical diagnosis and patient stratification. Moreover, multiple gut microbes and their metabolic products may be bioactive, thereby serving as future potential microbiome-targeting or -associated therapeutics. Such therapies could include new generation probiotics, prebiotics, fecal microbiota transplantations, postbiotics, and dietary modulators. However, microbiome research has also been associated with significant limitations, technical and conceptual challenges, and, at times, "over-hyped" expectations that microbiome research will produce quick solutions to chronic and mechanistically complex human disorders. Herein, we summarize these challenges and also discuss some of the realistic promises associated with microbiome research and its applicability into clinical application.

Advances in Gut Microbiota of Viral Hepatitis Cirrhosis

Although gut dysbiosis appears in 20%-75% of cirrhotic patients, there are limited data on microbiota profiles in viral hepatitis cirrhotics and its role in progression to cirrhosis. Further understanding on the relationship between gut dysbiosis and cirrhosis presents a unique opportunity in not only predicting the development of cirrhosis but also discovering new therapies. Recent advances have been made on identifying unique microbiota in viral hepatitis cirrhotics and adopting the microbiota index to predict cirrhosis. Therapeutic intervention with microbiome-modulating has been explored. Cirrhosis from viral infection has unique bacterial or fungal profiles, which include increased numbers of Prevotella, Streptococcus, Staphylococcaceae, and Enterococcus, as well as decreased Ruminococcus and Clostridium. In addition, the gut microbiota can stimulate liver immunity, effectively helping hepatitis virus clearance. In clinical settings, CDR, GDI, Basidiomycota/Ascomycota, specific POD, and so forth are efficient microbiota indexes to diagnose or prognosticate cirrhosis from viral hepatitis. FMT, probiotics, and prebiotics can restore microbial diversity in cirrhotic patients with viral hepatitis, decrease ammonia serum or endotoxemia levels, prevent complications, reduce rehospitalization rate, and improve prognosis. Cirrhotics from viral hepatitis had unique bacterial or fungal profiles, associated with specific metabolic, immune, and endocrinological statuses. Such profiles are modifiable with medical treatment. The role of gut archaea and virome, implementation of FMT, microbiota metabolites as adjuvant immunotherapy, and microbiota indexes for prognostication deserve attention.

Role of Gut Dysbiosis in Liver Diseases: What Have We Learned So Far?

Accumulating evidence supports that gut dysbiosis may relate to various liver diseases. Alcoholics with high intestinal permeability had a decrease in the abundance of Ruminnococcus. Intestinal dysmotility, increased gastric pH, and altered immune responses in addition to environmental and genetic factors are likely to cause alcohol-associated gut microbial changes. Alcohol-induced dysbiosis may be associated with gut barrier dysfunction, as microbiota and their products modulate barrier function by affecting epithelial pro-inflammatory responses and mucosal repair functions. High levels of plasma endotoxin are detected in alcoholics, in moderate fatty liver to advanced cirrhosis. Decreased abundance of Faecalibacterium prausnitzii, an anti-inflammatory commensal, stimulating IL-10 secretion and inhibiting IL-12 and interferon-γ expression. Proteobacteria, Enterobacteriaceae, and Escherichia were reported to be increased in NAFLD (nonalcoholic fatty liver disease) patients. Increased abundance of fecal Escherichia to elevated blood alcohol levels in these patients and gut microbiota enriched in alcohol-producing bacteria produce more alcohol (alcohol hypothesis). Some undetermined pathological sequences related to gut dysbiosis may facilitate energy-producing and proinflammatory conditions for the progression of NAFLD. A shortage of autochthonous non-pathogenic bacteria and an overgrowth of potentially pathogenic bacteria are common findings in cirrhotic patients. The ratio of the amounts of beneficial autochthonous taxa (Lachnospiraceae + Ruminococaceae + Veillonellaceae + Clostridiales Incertae Sedis XIV) to those of potentially pathogenic taxa (Enterobacteriaceae + Bacteroidaceae) was low in those with early death and organ failure. Cirrhotic patients with decreased microbial diversity before liver transplantation were more likely to develop post-transplant infections and cognitive impairment related to residual dysbiosis. Patients with PSC had marked reduction of bacterial diversity. Enterococcus and Lactobacillus were increased in PSC patients (without liver cirrhosis.) Treatment-naive PBC patients were associated with altered composition and function of gut microbiota, as well as a lower level of diversity. As serum anti-gp210 antibody has been considered as an index of disease progression, relatively lower species richness and lower abundance of Faecalibacterium spp. in gp210-positive patients are interesting. The dysbiosis-induced altered bacterial metabolites such as a hepatocarcinogenesis promotor DCA, together with a leaky gut and bacterial translocation. Gut protective Akkermansia and butyrate-producing genera were decreased, while genera producing-lipopolysaccharide were increased in early hepatocellular carcinoma (HCC) patients.

The Role of Probiotics in Nonalcoholic Fatty Liver Disease: A New Insight into Therapeutic Strategies

Nonalcoholic fatty liver disease (NAFLD) encompasses a broad spectrum of pathological hepatic conditions ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), which may predispose to liver cirrhosis and hepatocellular carcinoma (HCC). Due to the epidemic obesity, NAFLD is representing a global health issue and the leading cause of liver damage worldwide. The pathogenesis of NAFLD is closely related to insulin resistance (IR), adiposity and physical inactivity as well as genetic and epigenetic factors corroborate to the development and progression of hepatic steatosis and liver injury. Emerging evidence has outlined the implication of gut microbiota and gut-derived endotoxins as actively contributors to NAFLD pathophysiology probably due to the tight anatomo-functional crosstalk between the gut and the liver. Obesity, nutrition and environmental factors might alter intestinal permeability producing a favorable micro-environment for bacterial overgrowth, mucosal inflammation and translocation of both invasive pathogens and harmful byproducts, which, in turn, influence hepatic fat composition and exacerbated pro-inflammatory and fibrotic processes. To date, no therapeutic interventions are available for NAFLD prevention and management, except for modifications in lifestyle, diet and physical exercise even though they show discouraging results due to the poor compliance of patients. The premise of this review is to discuss the role of gut–liver axis in NAFLD and emphasize the beneficial effects of probiotics on gut microbiota composition as a novel attractive therapeutic strategy to introduce in clinical practice.

Systems biology perspective for studying the gut microbiota in human physiology and liver diseases

The advancement in high-throughput sequencing technologies and systems biology approaches have revolutionized our understanding of biological systems and opened a new path to investigate unacknowledged biological phenomena. In parallel, the field of human microbiome research has greatly evolved and the relative contribution of the gut microbiome to health and disease have been systematically explored. This review provides an overview of the network-based and translational systems biology-based studies focusing on the function and composition of gut microbiota. We also discussed the association between the gut microbiome and the overall human physiology, as well as hepatic diseases and other metabolic disorders.

Demystifying the manipulation of host immunity, metabolism, and extraintestinal tumors by the gut microbiome

The trillions of microorganisms in the gut microbiome have attracted much attention recently owing to their sophisticated and widespread impacts on numerous aspects of host pathophysiology. Remarkable progress in large-scale sequencing and mass spectrometry has increased our understanding of the influence of the microbiome and/or its metabolites on the onset and progression of extraintestinal cancers and the efficacy of cancer immunotherapy. Given the plasticity in microbial composition and function, microbial-based therapeutic interventions, including dietary modulation, prebiotics, and probiotics, as well as fecal microbial transplantation, potentially permit the development of novel strategies for cancer therapy to improve clinical outcomes. Herein, we summarize the latest evidence on the involvement of the gut microbiome in host immunity and metabolism, the effects of the microbiome on extraintestinal cancers and the immune response, and strategies to modulate the gut microbiome, and we discuss ongoing studies and future areas of research that deserve focused research efforts.

Characteristics of Gut Microbiota in Patients with Hypertension and/or Hyperlipidemia: A Cross-Sectional Study on Rural Residents in Xinxiang County, Henan Province

Human gut microbiota can be affected by a variety of factors, including geography. This study aimed to clarify the regional specific characteristics of gut microbiota in rural residents of Xinxiang county, Henan province, with hypertension and hyperlipidemia and evaluate the association of specific gut microbiota with hypertension and hyperlipidemia clinical indices. To identify the gut microbes, 16S rRNA gene sequencing was used and a random forest disease classifier was constructed to discriminate between the gut microbiota in hypertension, hyperlipidemia, and the healthy control. Patients with hypertension and hyperlipidemia presented with marked gut microbiota dysbiosis compared to the healthy control. The gut microbiota related to hypertension and hyperlipidemia may consist of a large number of taxa, influencing each other in a complex metabolic network. Examining the top 35 genera in each group showed that Lactococcus, Alistipes, or Subdoligranulum abundances were positively correlated with systolic blood pressure (SBP) or diastolic blood pressure (DBP) in hypertensive patients with treatment-naive hypertension (n = 63). In hypertensive patients undergoing anti-hypertensive treatment (n = 104), the abundance of Megasphaera or Megamonas was positively correlated to SBP. In the hyperlipidemia group, some of the top 35 genera were significantly correlated to triglyceride, total cholesterol, and fasting blood glucose levels. This study analyzed the characteristics of the gut microbiota in patients with hypertension and/or hyperlipidemia, providing a theoretical basis for the prevention and control of hypertension and hyperlipidemia in this region.

Zn(II)-curcumin solid dispersion impairs hepatocellular carcinoma growth and enhances chemotherapy by modulating gut microbiota-mediated zinc homeostasis

Zinc(II) complexes of curcumin display moderate cytotoxicity towards cancer cells at low micromolar concentrations. However, the clinical use of zinc(II) complexes is hampered by hydrolytic insolubility and poor bioavailability and their anticancer mechanisms remain unclear. Here, we investigated the efficacy and mechanism of action of a polyvinylpyrrolidone (PVP-k30)-based solid dispersion of Zn(II)-curcumin (ZnCM-SD) against hepatocellular carcinoma (HCC) in vitro and in vivo. In vitro assays revealed ZnCM-SD not only reduced the viability of HepG2 cells and SK-HEP1 cells in a dose-dependent manner, but also potently and synergistically enhanced cell growth inhibition and cell death in response to doxorubicin by regulating cellular zinc homeostasis. ZnCM-SD was internalized into the cells via non-specific endocytosis and degraded to release curcumin and Zn²⁺ ions within cells. The anticancer effects also occur in vivo in animals following the oral administration of ZnCM-SD, without significantly affecting the weight of the animals. Interestingly, ZnCM-SD did not reduce tumor growth or affect zinc homeostasis in HepG2-bearing mice after gut microbiome depletion. Moreover, administration of ZnCM-SD alone or in combination with doxorubicin significantly attenuated gut dysbiosis and zinc dyshomeostasis in a rat HCC model. Notably, fecal microbiota transplantation revealed the ability of ZnCM-SD to regulate zinc homeostasis and act as a chemosensitizer for doxorubicin were dependent on the gut microbiota. The crucial role of the gut microbiota in the chemosensitizing ability of ZnCM-SD was confirmed by broad-spectrum antibiotic treatment. Collectively, ZnCM-SD could represent a simple, well-tolerated, safe, effective therapy and function as a novel chemosensitizing agent for cancer.

Multiple “Omics” data-based biomarker screening for hepatocellular carcinoma diagnosis

The huge prognostic difference between early and late stage hepatocellular carcinoma (HCC) is a challenging diagnostic problem. Alpha-fetoprotein is the mostly widely used biomarker for HCC used in the clinic, however it’s sensitivity and specificity of is not optimal. The development and application of multiple biotechnologies, including next generation sequencing, multiple “omics” data, that include genomics, epigenomics, transcriptomics, proteomics, metabolomics, metagenomics has been used for HCC diagnostic biomarker screening. Effective biomarkers/panels/models have been identified and validated at different clinical levels. A large proportion of these have a good diagnostic performance for HCC, especially for early HCC. In this article, we reviewed the various HCC biomarkers derived from “omics” data and discussed the advantages and disadvantages for diagnosis HCC.

Gut Microbiota as an Objective Measurement for Auxiliary Diagnosis of Insomnia Disorder

Insomnia is a type of sleep disorder which is associated with various diseases’ development and progression, such as obesity, type II diabetes and cardiovascular diseases. Recent investigation of the gut-brain axis enhances our understanding of the role of the gut microbiota in brain-related diseases. However, whether the gut microbiota is associated with insomnia remains unknown. In the present investigation, leveraging the 16S rDNA amplicon sequencing of V3-V4 region and the novel bioinformatic analysis, it was demonstrated that between insomnia and healthy populations, the composition, diversity and metabolic function of the gut microbiota are significantly changed. Other than these, redundancy analysis, co-occurrence analysis and PICRUSt underpin the gut taxa composition, signaling pathways, and metabolic functions perturbed by insomnia disorder. Moreover, random forest together with cross-validation identified two signature bacteria, which could be used to distinguish the insomnia patients from the healthy population. Furthermore, based on the relative abundance and clinical sleep parameter, we constructed a prediction model utilizing artificial neural network (ANN) for auxiliary diagnosis of insomnia disorder. Overall, the aforementioned study provides a comprehensive understanding of the link between the gut microbiota and insomnia disorder.

Structural shifts in the intestinal microbiota of rats treated with cyclosporine A after orthotropic liver transplantation

Understanding the effect of immunosuppressive agents on intestinal microbiota is important to reduce the mortality and morbidity from orthotopic liver transplantation (OLT). We investigated the relationship between the commonly used immunosuppressive agent cyclosporine A (CSA) and the intestinal microbial variation in an OLT model. The rat samples were divided as follows: (1) N group (normal control); (2) I group (isograft LT, Brown Norway [BN] rat to BN); (3) R group (allograft LT, Lewis to BN rat); and (4) CSA group (R group treated with CSA). The intestinal microbiota was assayed by denaturing gradient gel electrophoresis profiles and by using real-time polymerase chain reaction. The liver histopathology and the alanine/aspartate aminotransferase ratio after LT were both ameliorated by CSA. In the CSA group, the numbers of rDNA gene copies of Clostridium cluster I, Clostridium cluster XIV, and Enterobacteriaceae decreased, whereas those of Faecalibacterium prausnitzii increased compared with the R group. Cluster analysis indicated that the samples from the N, I, and CSA groups were clustered, whereas the other clusters contained the samples from the R group. Hence, CSA ameliorates hepatic graft injury and partially restores gut microbiota following LT, and these may benefit hepatic graft rejection.

Gut Microbiota Changes in Patients with Bipolar Depression

This study aims to characterize the gut microbiota in depressed patients with bipolar disorder (BD) compared with healthy controls (HCs), to examine the effects of quetiapine treatment on the microbiota, and to explore the potential of microbiota as a biomarker for BD diagnosis and treatment outcome. Analysis of 16S-ribosomal RNA gene sequences reveals that gut microbial composition and diversity are significantly different between BD patients and HCs. Phylum Bacteroidetes and Firmicutes are the predominant bacterial communities in BD patients and HCs, respectively. Lower levels of butyrate-producing bacteria are observed in untreated patients. Microbial composition changes following quetiapine treatment in BD patients. Notably, 30 microbial markers are identified on a random forest model and achieve an area under the curve (AUC) of 0.81 between untreated patients and HCs. Ten microbial markers are identified with the AUC of 0.93 between responder and nonresponder patients. This study characterizes the gut microbiota in BD and is the first to evaluate microbial changes following quetiapine monotherapy. Gut microbiota-based biomarkers may be helpful in BD diagnosis and predicting treatment outcome, which need further validations.

Detection of Microbial 16S rRNA Gene in the Serum of Patients With Gastric Cancer

Aberrance in the blood bacterial microbiome has been identified and validated in several non-infectious diseases, including cancer. The occurrence and progression of gastric cancer has been found to be associated with alterations in the microbiome composition. However, the composition of the blood microbiome in patients with gastric cancer is not well-characterized. To test this hypothesis, we conducted a case-control study to investigate the microbiota compositions in the serum of patients with gastric cancer. The serum microbiome was investigated in patients with gastric cancer, atypical hyperplasia, chronic gastritis, and in healthy controls using 16S rRNA gene sequencing targeting the V1-V2 region. Our results revealed that the structure of the serum microbiome in gastric cancer was significantly different from all other groups, and alpha diversity decreased from the healthy control to patients with gastric cancer. The serum microbiome correlated significantly with tumor-node-metastasis (TNM) stage, lymphatic metastasis, tumor diameter, and invasion depth in gastric cancer. Three genera or species, namely, Acinetobacter, Bacteroides, Haemophilus parainfluenzae, were enriched in patients with gastric cancer, whereas Sphingomonas, Comamonas, and Pseudomonas stutzeri were enriched in the healthy control. Furthermore, the structure of serum microbiota differed between gastric cancer lymphatic metastasis and non-lymphatic metastasis. As a pilot investigation to characterizing the serum microbiome in gastric cancer, our study provided a foundation for improving our understanding of the role of microbiota in the pathogenesis of gastric cancer.

Fecal Microbiome Data Distinguish Liver Recipients With Normal and Abnormal Liver Function From Healthy Controls

Emerging evidence suggests that altered intestinal microbiota plays an important role in the pathogenesis of many liver diseases, mainly by promoting inflammation via the "intestinal microbiota-immunity-liver" axis. We aimed to investigate the fecal microbiome of liver recipients with abnormal/normal liver function using 16S rRNA gene sequencing. Fecal samples were collected from 90 liver recipients [42 with abnormal liver function (Group LT_A) and 48 with normal liver function (Group LT_N)] and 61 age- and gender-matched healthy controls (HCs). Fecal microbiomes were analyzed for comparative composition, diversity, and richness of microbial communities. Principal coordinates analysis successfully distinguished the fecal microbiomes of recipients in Group LT_A from healthy subjects, with the significant decrease of fecal microbiome diversity in recipients in Group LT_A. Other than a higher relative abundance of opportunistic pathogens such as Klebsiella and Escherichia/Shigella in all liver recipients, the main difference in gut microbiome composition between liver recipients and HC was the lower relative abundance of beneficial butyrate-producing bacteria in the recipients. Importantly, we established a fecal microbiome index (specific alterations in Staphylococcus and Prevotella) that could be used to distinguish Group LT_A from Group LT_N, with an area under the receiver operating characteristic curve value of 0.801 and sensitivity and specificity values of 0.771 and 0.786, respectively. These findings revealed unique gut microbial characteristics of liver recipients with abnormal and normal liver functions, and identified fecal microbial risk indicators of abnormal liver function in liver recipients.

Analysis of the Relationship Between the Degree of Dysbiosis in Gut Microbiota and Prognosis at Different Stages of Primary Hepatocellular Carcinoma

Gut microbiota dysbiosis is closely associated with primary hepatocellular carcinoma (HCC). Recent studies have evaluated the early diagnosis of primary HCC through analysis of gut microbiota dysbiosis. However, the relationship between the degree of dysbiosis and the prognosis of primary HCC remains unclear. Because primary HCC is accompanied by dysbiosis and dysbiosis usually increases the circulatory concentrations of endotoxin and other harmful bacterial substances, which further increases liver damage, we hypothesized that level of dysbiosis associated with primary HCC increases with the stage of cancer progression. To test this hypothesis, we introduced a more integrated index referred to as the degree of dysbiosis (D_dys ); and we investigated D_dys of the gut microbiota with the development of primary HCC through high-throughput sequencing of 16S rRNA gene amplicons. Our results showed that compared with healthy individuals, patients with primary HCC showed increased pro-inflammatory bacteria in their fecal microbiota. The D_dys increased significantly in patients with primary HCC compared with that in healthy controls. Moreover, there was a tendency for the D_dys to increase with the development of primary HCC, although no significant difference was detected between different stages of primary HCC. Our findings provide important insights into the use of gut microbiota analysis during the treatment of primary HCC.

Circulating Microbiota-Based Metagenomic Signature for Detection of Hepatocellular Carcinoma

Circulating microbial dysbiosis is associated with chronic liver disease including nonalcoholic steatohepatitis and alcoholic liver disease. In this study, we evaluated whether disease-specific alterations of circulating microbiome are present in patients with cirrhosis and hepatocellular carcinoma (HCC), and their potential as diagnostic biomarkers for HCC. We performed cross-sectional metagenomic analyses of serum samples from 79 patients with HCC, 83 with cirrhosis, and 201 matching healthy controls, and validated the results in the same number of subjects. Serum bacterial DNA was analyzed using high-throughput pyrosequencing after amplification of the V3-V4 hypervariable regions of 16S rDNA. Blood microbial diversity was significantly reduced in HCC, compared with cirrhosis and control. There were significant differences in the relative abundances of several bacterial taxa that correlate with the presence of HCC, thus defining a specific blood microbiome-derived metagenomic signature of HCC. We identified 5 microbial gene markers-based model which distinguished HCC from controls with an area under the receiver-operating curve (AUC) of 0.879 and a balanced accuracy of 81.6%. In the validation, this model accurately distinguished HCC with an AUC of 0.875 and an accuracy of 79.8%. In conclusion, circulating microbiome-based signatures may be potential biomarkers for the detection HCC.

Diagnostic and therapeutic potential of the gut microbiota in patients with early hepatocellular carcinoma

The gut microbiota is involved in the maintenance of the homeostasis of the human body and its alterations are associated with the development of different pathological conditions. The liver is the organ most exposed to the influence of the gut microbiota, and recently important connections between the intestinal flora and hepatocellular carcinoma (HCC) have been described. In fact, HCC is commonly associated with liver cirrhosis and develops in a microenvironment where inflammation, immunological alterations, and cellular aberrations are dramatically evident. Prevention and diagnosis in the earliest stages are still the most effective weapons in fighting this tumor. Animal models show that the gut microbiota can be involved in the promotion and progression of HCC directly or through different pathogenic mechanisms. Recent data in humans have confirmed these preclinical findings, shedding new light on HCC pathogenesis. Limitations due to the different experimental design, the ethnic and hepatological setting make it difficult to compare the results and draw definitive conclusions, but these studies lay the foundations for a pathogenetic redefinition of HCC. Therefore, it is evident that the characterization of the gut microbiota and its modulation can have an enormous diagnostic, preventive, and therapeutic potential, especially in patients with early stage HCC.

Why targeting the microbiome is not so successful: can randomness overcome the adaptation that occurs following gut manipulation?

The microbiome is explored as a potential target for therapy of bowel and systemic diseases. Fecal microbiota transplantation (FMT) has demonstrated efficacy in Clostridium difficile infection. However, clinical results regarding other diseases are modest, despite the abundant research on the microbiome over the last decade. Both high rate variability of the microbiome and adaptation to gut manipulations may underlie the lack of ultimate effects of FMT, probiotics, prebiotics, synbiotics, and antibiotics, which are aimed at restoring a healthier microbiome. The present review discusses the inherent variability of the microbiome and multiple factors that affect its diversity, as possible causes of the adaptation of the gut microbiome to chronic manipulation. The potential use of randomness is proposed, as a means of overcoming the adaptation and of restoring some of the inherent variability, with the goal of improving the long-term efficacy of these therapies.

Role of Gut Microbiota in Hepatocarcinogenesis

Hepatocellular carcinoma (HCC), one of the leading causes of death worldwide, has a causal nexus with liver injury, inflammation, and regeneration that accumulates over decades. Observations from recent studies have accounted for the involvement of the gut–liver axis in the pathophysiological mechanism responsible for HCC. The human intestine nurtures a diversified colony of microorganisms residing in the host ecosystem. The intestinal barrier is critical for conserving the normal physiology of the gut microbiome. Therefore, a rupture of this barrier or dysbiosis can cause the intestinal microbiome to serve as the main source of portal-vein endotoxins, such as lipopolysaccharide, in the progression of hepatic diseases. Indeed, increased bacterial translocation is a key sign of HCC. Considering the limited number of clinical studies on HCC with respect to the microbiome, we focus on clinical as well as animal studies involving the gut microbiota, with the current understandings of the mechanism by which the intestinal dysbiosis promotes hepatocarcinogenesis. Future research might offer mechanistic insights into the specific phyla targeting the leaky gut, as well as microbial dysbiosis, and their metabolites, which represent key pathways that drive HCC-promoting microbiome-mediated liver inflammation and fibrosis, thereby restoring the gut barrier function.

Harnessing immunotherapy for liver recipients with hepatocellular carcinoma: a review from a transplant oncology perspective

Without stringent criteria, liver transplantation for hepatocellular carcinoma (HCC) can lead to high cancer recurrence and poor prognosis in the current treatment context. Checkpoint inhibitors can lead to long survival by targeting coinhibitory pathways and promoting T-cell activity; thus, they have great potential for cancer immunotherapy. Therapeutic modulation of cosignaling pathways may shift paradigms from surgical prevention of recurrence to oncological intervention. Herein, we review the available evidence from a therapeutic perspective and focus on immune microenvironment perturbation by immunosuppressants and checkpoint inhibitors. Partial and reversible interleukin-2 signaling blockade is the mainstream strategy of immunosuppression for graft protection. Programmed cell death protein 1 (PD-1) is abundantly expressed on human liver allograft-infiltrating T-cells, which proliferate considerably after programmed death-ligand 1 (PD-L1) blockade. Clinically, checkpoint inhibitors are used in heart, liver, and kidney recipients with various cancers. Rejection can occur after checkpoint inhibitor administration through acute T-cell-mediated, antibody-mediated, or chronic allograft rejection mechanisms. Nevertheless, liver recipients may demonstrate favorable responses to treatment for HCC recurrence without rejection. Pharmacodynamically, substantial degrees of receptor occupancy can be achieved with lower doses, with favorable clinical outcomes. Manipulation of the immune microenvironment is a therapeutic niche that balances seemingly conflicting anticancer and graft protection needs. Additional translational and clinical studies emphasizing the comparative effectiveness of signaling networks within the immune microenvironment and conducting overall assessment of the immune microenvironment may aid in creating a therapeutic window and benefiting future liver recipients with HCC recurrence.

Integration of microbiology, molecular pathology, and epidemiology: a new paradigm to explore the pathogenesis of microbiome-driven neoplasms

Molecular pathological epidemiology (MPE) is an integrative transdisciplinary field that addresses heterogeneous effects of exogenous and endogenous factors (collectively termed 'exposures'), including microorganisms, on disease occurrence and consequences, utilising molecular pathological signatures of the disease. In parallel with the paradigm of precision medicine, findings from MPE research can provide aetiological insights into tailored strategies of disease prevention and treatment. Due to the availability of molecular pathological tests on tumours, the MPE approach has been utilised predominantly in research on cancers including breast, lung, prostate, and colorectal carcinomas. Mounting evidence indicates that the microbiome (inclusive of viruses, bacteria, fungi, and parasites) plays an important role in a variety of human diseases including neoplasms. An alteration of the microbiome may be not only a cause of neoplasia but also an informative biomarker that indicates or mediates the association of an epidemiological exposure with health conditions and outcomes. To adequately educate and train investigators in this emerging area, we herein propose the integration of microbiology into the MPE model (termed 'microbiology-MPE'), which could improve our understanding of the complex interactions of environment, tumour cells, the immune system, and microbes in the tumour microenvironment during the carcinogenic process. Using this approach, we can examine how lifestyle factors, dietary patterns, medications, environmental exposures, and germline genetics influence cancer development and progression through impacting the microbial communities in the human body. Further integration of other disciplines (e.g. pharmacology, immunology, nutrition) into microbiology-MPE would expand this developing research frontier. With the advent of high-throughput next-generation sequencing technologies, researchers now have increasing access to large-scale metagenomics as well as other omics data (e.g. genomics, epigenomics, proteomics, and metabolomics) in population-based research. The integrative field of microbiology-MPE will open new opportunities for personalised medicine and public health. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

A gut microbiome signature for cirrhosis due to nonalcoholic fatty liver disease

The presence of cirrhosis in nonalcoholic-fatty-liver-disease (NAFLD) is the most important predictor of liver-related mortality. Limited data exist concerning the diagnostic accuracy of gut-microbiome-derived signatures for detecting NAFLD-cirrhosis. Here we report 16S gut-microbiome compositions of 203 uniquely well-characterized participants from a prospective twin and family cohort, including 98 probands encompassing the entire spectrum of NAFLD and 105 of their first-degree relatives, assessed by advanced magnetic-resonance-imaging. We show strong familial correlation of gut-microbiome profiles, driven by shared housing. We report a panel of 30 features, including 27 bacterial features with discriminatory ability to detect NAFLD-cirrhosis using a Random Forest classifier model. In a derivation cohort of probands, the model has a robust diagnostic accuracy (AUROC of 0.92) for detecting NAFLD-cirrhosis, confirmed in a validation cohort of relatives of proband with NAFLD-cirrhosis (AUROC of 0.87). This study provides evidence for a fecal-microbiome-derived signature to detect NAFLD-cirrhosis.

Development of cirrhosis in individuals with non-alcoholic fatty liver disease can predict mortality. Here the authors used a unique twin and family cohort to identify a gut microbiome-derived 16sRNA signature that can detect cirrhosis in individuals with non-alcoholic fatty liver disease.

Gut microbial dysbiosis associates hepatocellular carcinoma via the gut-liver axis

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world. Gut microbiota has been demonstrated to play a critical role in liver inflammation, chronic fibrosis, liver cirrhosis, and HCC development through the gut-liver axis.

DATA SOURCES

Recently there have been several innovative studies investigating gut microbial dysbiosis-mediated enhancement of HCC through the gut-liver axis. Literatures from January 1998 to January 2018 were searched in the PubMed database using the keywords "gut microbiota" and "hepatocellular carcinoma" or "liver cancer", and the results of experimental and clinical studies were analyzed.

RESULTS

Gut microbial dysbiosis accompanies the progression of alcoholic liver disease, non-alcoholic fatty liver disease and liver cirrhosis, and promotes HCC progression in an experimental mouse model. The immune system and key factors such as Toll-like receptor 4 are involved in the process. There is evidence for gut microbial dysbiosis in hepatitis virus-related HCC patients.

CONCLUSIONS

Gut microbial dysbiosis is closely associated with hepatic inflammation disease and HCC through the gut-liver axis. With the enhanced understanding of the interactions between gut microbiota and liver through the gut-liver axis, new treatment strategies for HCC are being developed.

Alteration in gut microbiota associated with hepatitis B and non-hepatitis virus related hepatocellular carcinoma

BACKGROUND

The onset of hepatocellular carcinoma (HCC) ranked fifth malignancies all over the world. Increasing evidences showed that the distribution of HCC was related to the incidence of chronic hepatitis B virus (HBV) infection and other factors, such as alcoholism, aflatoxin B1 ingestion and obesity. Recent studies demonstrated that gut dysbiosis plays an important role in liver diseases. However, the researches on gut microbiota of HBV and non-HBV non-HCV related HCC have not been reported. In this study, we investigated the differences between the gut microbiota of HBV related HCC (B-HCC) and non-HBV non-HCV related HCC (NBNC-HCC), finally found some potential bacteria, linking different pathological mechanism of both types of HCCs.

RESULTS

We carried out 16S rRNA analyses in a cohort of 33 healthy controls, 35 individuals with HBV related HCC (B-HCC) and 22 individuals with non-HBV non-HCV (NBNC) related HCC (NBNC-HCC). We found that the species richness of fecal microbiota of B-HCC patients was much higher than other two groups. Interestingly, the feces of NBNC-HCC patients harbored more potential pro-inflammatory bacteria (Escherichia-Shigella, Enterococcus) and reduced levels of Faecalibacterium, Ruminococcus, Ruminoclostridium which results in decrease potential of anti-inflammatory short-chain fatty acids. The feces of NBNC-HCC patients had relatively fewer abundance of multiple biological pathways related to amino acid and glucose metabolism, but high level of transport and secretion in some types. However, the B-HCC patients had opposite results of bacterial composition and associated multiple biological pathways versus NBNC-HCC patients. Meanwhile, we found that aberrant network of gut microbiota occurred differently in B-HCC and NBNC-HCC patients.

CONCLUSIONS

Our study indicated that B-HCC and NBNC-HCC patients showed differential abundance of bacteria involved in different functions or biological pathways. We suggested the modification of specific gut microbiota may provide the therapeutic benefit for B-HCC and NBNC-HCC.

HOTAIR/miR-214-3p/FLOT1 axis plays an essential role in the proliferation, migration, and invasion of hepatocellular carcinoma

BACKGROUND

Long non-coding RNA (lncRNA) Hox transcript antisense intergenic RNA (HOTAIR) has been reported to play an important role in hepatocellular carcinoma (HCC) progression. Although there is evidence on HOTAIR being associated with HCC progression, the underlying mechanism remains to be further clarified.

METHODS

HOTAIR, miR-214-3p and FLOT1 expression were measured by quantitative real-time PCR or western blot. Cell proliferation, migration, and invasion were displayed by transwell assay, MTT, and colony formation assay. The relationship between HOTAIR, miR-214-3p, and FLOT1 was investigated by luciferase reporter assay. Tumor suppressive effect of HOTAIR was displayed by HepG2 xenografting to nude mice.

RESULTS

HOTAIR and FLOT1 expression were significantly up-regulated, whereas miR-214-3p was obviously down-regulated. Also, down-regulation of HOTAIR and FLOT1 as well as up-regulation of miR-214-3p inhibited cell proliferation, invasion, and migration. Intriguingly, the effects of miR-214-3p overexpression on HCC cells were rescued by high expression of HOTAIR. Otherwise, HOTAIR regulated FLOT1 expression through targeting miR-214-3p in HCC cells. Simultaneously, low HOTAIR expression inhibited FLOT1 expression by up-regulating miR-214-3p, which suppressed tumor growth in vivo.

CONCLUSION

HOTAIR expression indirectly regulated FLOT1 expression through endogenous competition with miR-214-3p. HOTAIR/miR-214-3p/FLOT1 axis affected the cell proliferation, migration, and invasion of HCC.